Internal-combustion engine.



(a. J. RATHBUN.

INTERNAL COMBUSTION ENGINE.

APPLtCATION FILED DEC.2i. 1914.

1,1 92,456- Patented July 25, 1916,

3/ 4 s SHEETS-SHEET 1.

G. J. RATHBUN. INTERNAL-COMBUSTION ENGINE.

APPLICATION FILED 020.21, 1914 Patented July 25, 1916.

3 SHEETS-SHEET 2- INTERNAL COMBUSTION ENGINE.

APPLICATION man DEC. 21, 1914.

1 1 92,45 6. Patented July 25, 1916.

3 SHEETS-SHEET 3.

t Zf 27 F )2 5 3 I J7 F "l/jly/ 4% 1 if 44 i I f 1 L l 4321 -1 1% f" mw/wtm/ 9 fewzmw,

M-v-W GEORGE J". RATHBUN, OF TOLEDO, OHIO.

INTERNAL-COMBUSTION ENGINE.

Specification of Letters Patent.

Patented July 25, 1916.

Application filed December 21, 1914. Serial No. 878,414.

To all whom it may concern:

Be it known that I, GEORGE J. RATHBUN, a citizen of the United States of America, and a resident of Toledo, in the county of Lucas and State of Ohio, have invented certain new and useful Improvements in Internal-Combustion Engines, of which the following is a specification.

My invention relates to improvements in internal combustion engines, and particularly to multi-cylinder internal combustion engines of the tandem type, though it embodies features of valve gear not limited to tandem engines.

My invention consists in the novel valve gear herein illustrated and described and in other features hereinafter pointed out.

The objects of my invention are to increase the power of internalengines per unit of piston displacement; to provide an engine design readily adaptable for operation on either natural gas or producer gas, as well as on other fuels, and which, when working on producer gas, may operate with a capacity equal, or nearly equal, to that of its operation on natural gas; to improve the valve gear of internal combustion engines, particularly of tandem internal combustion engines, and generally to produce an engine which is simple, compact, efficient and relatively inexpensive in construction.

I will now proceed to describe my invention with reference to the accompanying drawings, and will then point out the novel features in claims.

In the drawings: Figure 1 shows an elevation and partial longitudinal section through I the admission valves of a vertical tandem engine embodying my invention, and Fig. 2 is a similar vertical section through the exhaust valves of such engine. Fig.3 is a diagrammatic sectional view illustrating use of air-compressing means and valve means such as shown in Figs. 1 and 2, for the supply of scavenging air to the engine cylinders, and illustrating means whereby the lower end of the lower cylinder may also be used as an air compression cylinder, the plane of section of Fig. 3 being transverse to the crank shaft; and Fig. 4: is a diagrammatic sectional view illustrating the provision of means, both for the supply of scavenging air and for the supply of air to dilute, and to raise the pressure of, the entering explosive charge, this view being a vertical section through the centers of the compressed air receivers on a plane at right angles to the plane of section of Fig. 3.

In the drawings, numeral 1 designates the upper working cylinder and numeral 2 the lower working cylinder of a tandem internal combustion engine, which, generally, is of the four cycle type; numerals 3 and a designate the pistons of cylinders 1 and 2 respectively, and numeral 5 designates a piston rod connecting said pistons and passing through a stufling box 6 located between cylinders 1 and 2.

7 designates the crank shaft, 8 the crank pin and 9 the connecting rod.

10 designates the valve shaft, connected to crank shaft 7 by gears 11 and 12 having a ratio of 2 to 1 as is common in four cycle engines. Shaft 10 carries an eccentric 13 for operating the admission valves, and another eccentric 14c for operating the exhaust valves. The admission valve gear and exhaust valve gear are similar except in respects hereinafter noted.

Admission valve gcam.The strap of eccentric 13 operates an eccentric rod 15 guided at its upper end by a cross head 16 of the piston type, to which cross head is connected a bent valve-operating member 171S19, the elbow member of which actuates a pivoted rocker 20 for operating the admission valve 21, of the lower cylinder 2; while the upper member 19 is connected to another rocker 22, for operating the admission valve 23 of the upper cylinder, 1, and is also connected to a rocker arm 24, pivoted at 25, and thence by a link 26, to a further cross head 27 and certain other valves to be mentioned hereafter. Rocker 20 engages a so-called roller path lever 28 pivoted at 29 to a fixed portion of the engine frame and connected at its front end to the stem of the admission valve 21. A spring 30 tends to hold valve 21 closed. connected to the stem of valve 23, engages a fixed roller path cam 31. Roller path rockers such as 20 and 22, and cooperating roller path cams such as 28 and 31, are in themselves well known features of valve gear of internal combustion engines, and in themselves require no special description. But so far as I know such roller-path members have not been used heretofore, for the operation of two admission valves of the two cylinders of a tandemtype engine, the roller path levers being operated by a single valve operating member such as the member 17-18 Rocker 22, which is,

19. The action of these roller path'valve gears being well known, it will be understood that during one down stroke of the two pistons 3 and 4. the upper valve, 23, will be opened, while during the next =down stroke of such pistons the lower admission valve, 21, will be opened. Such action follows from the fact that somewhat after the mid-point in the downward motion of the member 171819 has been passed, the rocker 20 acts on the swinging roller path lever 28 to depress that lever and open valve 21, while somewhat after themid-point in the upward movement of member 17 18 19 has been passed, the rocker or roller path lever 22 acts upon the roller path cam 31 and thereby (owing to the forms of the cooperating surfaces of members 22 and '31-) valve 23 is depressed or opened. Since shaft 10 rotates at half the speed of crank shaft 7 the timing is right for the opening of valve 21 during one downward stroke of the pistons, and for the opening of the valve 23 during the next downward stroke of the pistons. The valve gear, as shown, will close each admission valve during the early portion of the compression stroke'in the corresponding cylinder, it being common practice to close the admission valve in the compression stroke rather than in the preceding admission stroke.

The valve 21, it will be noted, is mounted to move along an oblique axis, its SCGHLPIO- jectingat the side of the engine. This arrangement permits the'two cylinders, l and 2, to be located quite close together, rela tively, and so reduces materially the height of the engine, as compared with what its height would be if the valve 21 werelocated, with respect to cylinder 2, the same as valve 23 is located with respect to cylinder 1. Since the axis of valve 21 is oblique, it is convenient to form the valve operating member 17 -1819, as a bent member, as shown, since this permits the valve shaft 10 to be in the same position that it would occupy if that valve shaft were to operate valve 23 only. 7

Supplemental air val 0e gear.-Upon the other side of the engine I have indicated a cylindrical valve chamber 32, which, con veniently, is located within the usual water cooled exhaust manifold 33 of the engine. The piston crosshead, 27, previously mentioned, works within, and closes, the upper end of this cylinder 32. Thelower end of said cylinder is closed by a head 34. To the cross head 27 is connected a valve rod 35 upon which are mounted hollow piston and 38 together coact with ports 41 connecting an admission space 42 with said valve chamber 32. In addition, there is a .port 43, open at all times, connecting the lower end of cylinder 1 with valve chamber 32.

The operation of the engine is as follows: F or the present it may be assumed that the engine has exhaust valves operating the same as in an ordinary four cycle engine. The construction of-the exhaust valve gear is illustrated in Fig. 2, and will be referred to hereafter; but so far as the functions of the engine are concerned, these valves are operated the same as in an ordinary four cycle engine. So far'as the functions of the engine are concerned, the admission valves, 21 and 23, are also operated the same as in an ordinary four cycle engine. By the operation of the piston 3, air, admitted through connection 45 past valves 37 and 38 as hereinafter described, is compressed in the lower end of cylinder 1 and in valve chamber 32. During the admission period in each of cylinders 1 and 2, (which admission periods, as will be understood, occur alternately in cylinder 1 and in cylinder 2) an explosive charge is drawn into the one cylinder or the other; through its admission valve, 23 or 21. When the piston, 3 or 4, uncovers the corresponding side admission port, 39 or 10, the slide valve, 36 or 38, guarding such admission port, 39 or 40, is then in such position that, with the port, 39 or40, open, air compressed as'previously described, in chamber 32 will pass into the corresponding cylinder, 1 or 2, raising the pressure in that cylinder. The charge admitted'through the main admission valves, 21 and 23, is ordinarily abnormally rich; and this charge isdiluted, by the air, so entering through the side port, 39 or 40, thereby bringing the cylinder charge, which as above stated, was initially abnormally rich, tothe proper proportions,'but at the same time giving that charge a pressure considerably greater than that of the atmosphere. In a word,'the effect of the-admis sion of an abnormally rich charge at atmospheric pressure through the main admission Valve of the cylinder, followed by the admlssion through-the side port of that cylinder of a further quantity of air at pressure above atmosphere, is to give the cylinder a charge of proper proportions but of greater thanatmospheric pressure. It will be obvi ous thatby this means the power of the engine per unit of piston displacement is very considerably increased. In Fig. 1 valve 36 is shown as closing the side port 39 of cylinder 1; valve 38 is shown as opening the side port 40 of cylinder 2 and as closing air admission ports 41. The pistons 3 and 4 are near'the lower ends of their stroke, piston 4 being about to open the side port 40 to admit the high pressure air to cylinder 2, as just described. It will be obvious that as the down stroke proceeds port 40 will be opened, and then, shortly after the beginning of the ensuing up stroke, port 40 will be closed againby piston 4, valve 38 will open air ports 41, and as piston 3 continues to rise air will be drawn through ports 41 into compression space 32 and into the lower end of cylinder 1, beneath piston 3. It will further be apparent that at the beginning of the next succeeding downstroke of the pistons 3 and 4, (the working stroke in cylinder 2) air admission ports 41 will be closed by valve 37 and will continue to be closed until, piston 3 having opened side port 39 near the lower end of the stroke of that piston and side port 39 being then uncovered by slide valve 36, air under pressure will be admitted to cylinder 1, such admission being cut off again shortly after the piston 3 begins to rise, and valve 37 then opening the air admission ports 41, such air ports continuing open until, as the working stroke in cylinder 1 begins, valve 38 closes the air admission ports 41. The inertia of the charge entering through main admission valve 21 or 23, as the case may be, is suflicient to prevent forcing back of such charge by the air entering through side port 39 or 40, as the case may be, at higher pressure than atmosphere, notwithstanding that admission valves 21 and 23 are not closed until after the admission of such higher pressure air through the said side ports.

By such simple means as the provision of the valve chamber and compression space 32, with the lateral ports connecting that valve chamber with cylinders 1 and 2 and with the port 43 connecting the compressed space with the lower end of cylinder 1, and with the simple slide valve gear illustrated and operated by the lever connection 2624 to the main admission valve gear, I am able to supply a considerable quantity of air, under pressure considerably above that of the atmosphere, to the two cylinders 1 and 2 in alternation, and at proper time to dilute and raise to higher pressure the rich charges previously admitted, at about atmospheric pressure, to said cylinders 1 and 2. By this simple means I am enabled, therefore, to raise the power of an engine working on lean gas, such as producer gas, to about the power which that engine would have, without the compression chamber 32 and associated parts, if working on natural gas, illuminating gas, or other relatively rich gas. Correspondingly the power of an engine, without the compression chamber 32 and associated parts, working on natural gas, illuminating gas, etc., may be raised considerably, by the addition of such compression chamber 32 and associated parts.

A further important advantage of the valve gear (and this applies both to the valve gear of compression chamber 32, to the valve gear which operates the mainadmission valves 21 and 23, and to the exhaust Valve gear hereinafter described and illus trated in Fig. 2) is, that the valve gear as a whole is practically noiseless in operation and is free from violent shocks. Since the valve chamber 32 is water cooled, the slide valves within that chamber are kept relatively cool, and so operate with very little wear.

I commonly provide a well known type of balanced lift valve 46, for controlling the admission of air to the space 42, and a similar type of mixing valve 47 for controlling the admission of the charge to the admission manifold 48 and thence to the cages of the main admission valve 21 and 23. The two valves, 46 and 47, are commonly connected to a single rocker 49 pivoted at 50 and adjustable by a governor rod 51 and a suitable fly ball governor (not shown) driven from the crank shaft or from the valve gear shaft in the ordinary way. In this manner I am able to regulate the supply of the explosive mixture and of the auxiliary air with maintenance of substantially uniform proportions of the ultimate mixture formed in the engine cylinders.

Exhaust 'val'ue germ-As above stated, the exhaust valve gear, illustrated in Fig. 2, is very similar to the admission valve gear, comprising an eccentric 14 mounted upon the valve shaft 10, an eccentric rod 15 cross head 16 a bent valve operating member 17 -1819 the elbow member 18 of which actuates a pivoted rocker 20 for operating the exhaust valve 21 of the lower cylinder 2, while the upper member, 19*, is connected to another rocker, 22*, for operating the exhaust valve 23 of the upper cylinder, 1; rocker 20 engaging a roller path lever 28 and rocker 22 engaging a fixed roller path cam 31*; the operation of this exhaust valve mechanism being obvious from the previous description of the operation of the admission valve mechanism.

For convenience in illustration I have indicated the two admission valves 21 and 23, and the two exhaust valves 21 and 23 as if each were located in the central plane of section of the cylinders 1 and 2; but it will be understood that in practice the two admission valves are located to one side of the central plane and the'two exhaust valves located to the other side of the central plane, the drawings being diagrammatic to the extent that they show the admission and exhaust valves on the central plane instead of to one side of the central plane as they would be in practice. This is a matter readily un derstood by those skilled in the art and it is common in the art to illustrate, as if on the as closing side port 40, valve 37 being shown as having just closed end ports 41 and valve 36 being shown as uncovering the side port 39; which port, however, will shortly be closed by piston 3 as that piston descends.

Scavengz'ngoaloe gear.It will be obvious that air compressing and valve means, simi lar to'that illustrated, in Figs. 1 and 2, for the supply of air under pressure to the en-' gine cylinders to dilute, and to raise the pressure of, the explosive charge, maybe used for the introduction into the cylinders at the end of the working stroke of air under pressure to scavenge said cylinders,'i. 6., to aid in sweeping the burnt gases out ofsaid cylinders. This is illustrated in ,Fig. 3, in whichfigure, for the sake of simplicity, I have indicated the working parts of theengine in outline and, in the main, insingle lines, as is common in diagrammatic illustration of internal combustion engines. For the supply of such scavenging air, air compressing means and valve means of precisely the same nature as that employed for the supply and admission of supplemental air, may be employed; but it is convenient to 0perate the valves controlling the supply of scavenging air from the exhaust valve gear of the engine, rather than from the admission valve gear. I have designated the valve gear 'parts of this scavenging-air supply means by the same numerals,primed, as are employed, in Figs. 1 and 2, to designate the corresponding parts of the supplemental air valve means. The operation of the scavenging air valve means will be obvious from the preceding description. As each piston 3 or 1 uncovers its corresponding lateral port, 39

.or 10' at the end of the workin stroke air under pressure rushes into that cylinder from the receiver 32, to sweep up through the cylinder and toward the exhaust port thereof, the burnt gases in the cylinder.

It will be obvious that the engine-may be provided ,with both the supplemental-air supply means and the scavenging-airsupply means. This is illustrated in Fig. 4, wherein I have shown, diagrammatically, a supplemental-air receiver, 32, with associated parts, and a scavenging-air receiver, 32, with as sociated parts, the slide valves controlling the supplemental air being operated by the link 26 and thence by the admission valve gear of the engine, the scavenging air valve means being operated by the link 26 and thence by the exhaust valve gear of the en-' gine. Particularly when the engine is provided both with means for admitting supplemental-air to the cylinders, and with means for admitting scavenging air to the cylinders, it may be desirable to employ the lower cylinder, 2, as well as the upper cylinder, 1, as an air compressor. In Figs. 3 and 4: Ihave indicated how this may be done, the lower cylinder 2 being closed at its lower end and provided with ports 43 leading to the two compressed air receivers 32 and 32. In suchcase, of course, a separate cross head, 52, must be provided. I have indicated a cross head of the piston type working in a guide cylinder 53.

What I claim is 1. In an engine, the combination of two tandem arranged cylinders, pistons therefor, aerank shaft, a connecting rod, corresponding valves for said cylinders, and valve gear for operating corresponding valves of both cylinders, comprising a single reciprocating member and roller-path valve-operating means for each such valve operated thereby, and arranged, the one to operate its valve during one portion of the movement of said reciprocating member, the other to operate a crank shaft, a connecting rod, correspond ing valves for said cylinders, and valve gear for operating corresponding valves of both cylinders, comprising a single reciprocating member and roller-path valve-operating means for each-such valve, such roller-path means for one valve'comprising a swinging rocker pivotally mounted at one end and pivotally connected at the other end to said reciprocating member, and a coacting rocker pivotally mounted at one end and connected at the other end to the corresponding valve, the roller-path means for the other valve comprising a fixed roller path cam and a I'OllGI'rlDfitll lever to coacttherewith and connected at one end to the corresponding valve and connected at another point to the said reciprocating member.

3. In an engine, the combination of two tandem arranged cylinders, pistons therefor, a crank shaft, a connecting rod, corresponding valves for said cylinders, a valve shaft driven from said crank shaft, an eccentric on :sa-idvalve shaft, an eccentric rod, a reciprocatingmember reciprocated by such eccen-- alternation, each of said roller-path valveoperating means comprising a roller-path lever pivoted to said reciprocating member and a complementary roller-path member cooperating therewith, one of said rollerpath members being operatively connected with the valve. I I

4. In anengine, the combination of two tandem arranged cylinders, pistons therefor, a crank shaft, a connecting rod, corresponding valves for said cylinders, the valve for the cylinder nearest the crank shaftbeing located onan oblique axis, andvalve gear, for operating the valvesof said cylinders comprising a singlereciprocating member, and valve-operating means jfor each such valve operatedthereby, the said I'GCIPI'OCtttr,

ing member beingofbent formin proximity to the oblique'valve, whereby room is pro vided between said reciprocating member and the said'oblique valve for the means which operates such valve and which is operated by said reciprocating member.

5. In an internal combustion engine, the combination with a plurality of single acting internal combustion cylinders, pistons therein, a crank shaft and means forcommunicating motion from said pistons to said crank shaft, one ofsaid cylinders arranged tor air compression in its end opposite its internal combustion end, of corresponding valves for said cylinders, valve gear for operating such corresponding valves of both cylinders comprising a single reciprocating member, which operates both valves, and means for admitting air compressed in the air compression end of one of said cylinders into both said cylinders in alternation comprising valve gear also operated by said reciprocating member.

6. In an internal combustion engine, the combination with a; plurality of single acting internal combustion cylinders, pistons therein, a. crank shaft and means for communicating motion from said pistons to said crank shaft, one of said cylinders arranged for air compression in its end opposite its internal combustion end, of corresponding valves for said cylinders, valve gear for operating such corresponding valves of both cylinders comprising a single reciprocating member, which operates both valves, and means for admitting air vcompressed in the air compression end of one of said cylinders into both said cylinders in alternation comprising slide valve gear and means-connecting same to said vreciprocating member for operation thereby, t

7. In an internal combustion engine, the

combination witha plurality of single acting internal combustion cylinders, pistons therein, acrank shaft and means for com;

municating motion from said pistons tosaid crank shaft, one of said cylinders arranged: for air compression inits end opposite its: internal combustion end, of corresponding combination with a plurality of internal combustion cylinders, one of whichis ar-- ranged for internal combustlon operation at one endonlyfand is arranged for air compression at the other end, pistons within said cylinders, a crank shaft; and means for communicating motion from said pistons to said crank shaft, said cylinders provided with charge admission means and with lateral admission ports, opened by the pistons near the ends of their strokes, for the admission of compressed air from, such compression cylinder to the internal combustion spaces of such cylinders, a conduit for such com pressed air connected with said lateral admission ports and in open communication with said compression cylinder and provided with valve controlled inlet for admitting air therethrough to said cylinder, and valve means controlling such lateral admission ports.

9. In an internal combustion engine, the combination with a plurality of internal combustion cylinders, one'o'f which is arranged for internal combustion operation at one end only and is arranged for air compression at the other end, pistons within said cylinders, a crank shaft and means for c0n1munieating motion from said pistons to said crank shaft, said cylinders provided with charge admission means and with lateral admission ports, opened by the pistons near the ends of their strokes, for the admission of compressed air from such compression cylinder to the internal combustion spaces of such cylinders, a valve chamber in open commu nication with said compression cylinder to which said lateral ports are connected, valve controlled means for admitting air into said chamber and compression cylinder, valves for said lateral ports in said valvechamber, and means for operating said valves.

rangedfor internal combustion operation at one end only and is arranged for air compression at the other end, pistons within said cylinders, a crank shaftand means'for com-. munlcating motion from said plstons to said crank shaft, said cylinders provided with charge admission means and withlateral admission ports, opened by the pistons near the end of their strokes, for the admission of compressed air fromsuch compression cylinder into the internal combustion spaces of such cylinders, a valve chamber connectedto said lateral ports and in open communication with the compression cylinder, and provided with an air admission port, and-- valves within said" valve chamber control ling the'passage of'airfi'om said valve'chamberto said lateral'ports, andco'ntrol-ling the admission-of air to said valve-chamber, andthenceto, said compression cylinder.

, 11. In an"int'ernal combustionengine, the

combination with a; plura'lity'of internal combustion cylinders, one of which is arranged'for internal combustion operation atone end' only and is arranged for air coinpression at-the other end, pistons within-said cylinders, a crankshaft and means for com mun-icat'ing motion from said pistons to said crank shaftfsaid cylinders provided with charge admission-means and with lateral admission ports, opened by the plstons nearthe ends of'tlieir strokes, for the admission of compressed air from such compression cylinder to the internal combustionspaces of suchcylinders, a valve chamber connected to said lateral-ports and in open CO111I111lIll Catl0n W1tl1 the compression cylinder, and provided with M12311 admission port, and

slide valves within said' valve chamber con trollingthe passage of air from said valve chamber to said lateral ports, and control v ling the admissionof air tosaid valve'chamber, and thence to said compression cylinder.

12. In an internal combustion engine, the

combination with a plurality of internal combustion cylinders one of which is arranged for internal combustion operation at one end only and is arranged for air coinpression at the other end, valves for the in ternalcombustion spaccs'of said cylinders,

, operatingmeans for saidvalvescomprising a single reciprocating member for corresponding valves of both cylinders, pistons within said cyl nders, a crankv shaft" and means for COID'DIHHICatIHglnOtlOIl fromsa d pistons to said crank shaft, said cylinders provided With-lateral admission ports con-- trolled by the pistons, for the admission of compressedfi'air from such compression cylinder to the internal combustion spaces of; such cylinders, a valve chamber connected to said lateral ports and connected tothe-co npression cylinder,-and provided with anair-admisslon port, and slide valves within said valve chamber, controllingathe' pas sage of air from said valve chamber to said lateral ports, and controllingthe admission .of air to said valvefchamben andth'enceto said compression cylinder,- and" means connecting said sli'devalves' to the reciprocatingvalve-operating means for operation thereby;

13. Inan internal combustionengine,-tl 1e' combination'wi'th' a plurality of internal combustion cylinders, one OfWlllCll is ari waranged for internal combustion operation at one end only, and is arranged for air compression at the other end, pistons within said cylinders, a crank shaft'and means for communicating motion from said pistons to said crank shaft, said cylinders provided with exhaust means and with lateral scavengingair admission ports opened by the pistons near the ends of their strokes, for the admis' sion of compressed air from such compression cylinder to the internal combustion spaces} of such cylinders, and valve means controlling such lateral admission ports.

-14. In an internal combustion engine, the combination with pluralityof internal combustion cylinders, one of which is are, e ranged for internal combustion operation at one'end only and is arranged for air com-' pression atlthe'other end, pistons Within said eyl1nders-,,a crank shaft and meansfor communicating motion from said pistons to said crank shaft, saidv cylinders provided with exhaust means and with lateral scavengingair admission ports, opened by the pistons near the ends of their strokes, for the admission of compressed air from such compression cylinder to the internal combus tion spaces of such cylinders, a valve chamber to which said lateral ports are connected, valve means for delivering air compressed in such compression cylinder to said valve chamber, such means controlling passage of compressed air from such chamber to said lateral ports, and means for operating such valve means.-

15. In an internal combustion engine, the combination with a plurality of internal combustion cylinders, one of which is arranged. for internal combustion operation at one end only and is arranged for air compression at the other end, pistons within said cylinders, a crank shaft and means for communicating'inotion from saidpistons to said crankshaft, said cylinders provided 'with exhaust means and with lateral scavenging-air admission ports, opened by; the pistons near'the ends of their strokes, for the admission of compressed air fromsuch compression cylinder to theinternal combustion spaces of such cylinders, a valve chamber connected to said'lateral ports and connected tothej compression cylinder, and provided 7 with an air admission port, and valves within said valve chamber'controlling the passage otair from said valve chamber to said lateral ports, and controlling the admission of air to said valve chamber, and'thence to said compression cylinder..

16. In an intcrnal combustio-nengine, the

combination with a plurality of internal,

combustion cylinders, one of which is arranged for internal combustion operation at one end only and is'arranged for air com-,

pression at-the otherend, pistons within said cylinders, a crank shaft and means for come inunicating motion from said pistons to said crank shaft, said cylinders provided with exhaust means and with lateral scavengingair admission ports, opened by the pistons near the ends of their strokes, for the admission of compressed air from such compression cylinder to the internal combustion spaces of such cylinders, a valve chamber connected to said lateral ports and connected to the compression cylinder, and provided with an air admission port, and slide valves within said valve chamber controlling the passage of air from said valve chamber to said lateral ports, and controlling the admission of air to saidvalve chamber, and thence to said compression cylinder.

17. In an internal combustion engine, the combination with a plurality of internal combustion cylinders one of which is arranged for internal combustion operation at one end only and is arranged for air compression at the other end, valves for the internal combustion spaces of said cylinders, operating means for said valves comprising a single reciprocating member for corresponding valves of both cylinders, pistons within said cylinders, a crank shaft and means for communicating motion from said pistons tosaid crank shaft, .said cylinders provided with exhaust means and with lateral scavenging-air admission ports, controlled by the pistons, for the admission of compressed air from such compression cylinder to the internal combustion spaces of such cylinders, a valve chamber connected to said lateral ports and connected to the compression cylinder, and provided with an air admission port, and slide valves within said valve chamber controlling the passage of air from said valve chamber to said lateral ports, and controlling the admission of air to said valve chamber and thence to said compression cylinder, and means connecting said slide valves to the reciprocating valveoperating means for operation thereby.

18. In an internal combustion engine, the combination with an engine cylinder arranged for internal combustion operation at one end and arranged for air compression at the other end, a piston within said cylinder, a crank shaft and means for communicating motion from said piston to said crank shaft, said cylinder provided With charge admisthrough such lateral port of scavenging air.

near the end of the working stroke.

19. An internal combustion engine com prising an engine cylinder and'piston, said cylinder arranged for internal combustion operation the engine being provided with air compression means, said cylinder being pro vided with admission and exhaust valves and with separate valve gear for the admission and the exhaust valves, means operated by one of said valve gears for the supply of supplemental air to said cylinder, and means operated by the one valve gear for the supply of scavenging air to said cylinder.

7 '20. In an internal combustion engine, the combination with a plurality of internal combustion cylinders, one of which is arranged for internal combustion operation at one end only and is arranged for air compression at the other end, pistons within said cylinders, a crank shaft and means for communicating motion from said pistons to said crank shaft, said cylinders provided with charge admission means, and with lateral admission ports opened by the pistons near the ends of their strokes for the admission of compressed air from such compression cylinder to the internal combustion spaces of such cylinders, a valve chamber arranged substantially parallel with said cylinders and connecting said lateral admission ports with each other and with said compression cylinder, and reciprocating valves and a con necting valve, rod within said valve chamber arranged to control said lateral admission ports and the inlet of air into said chamber. In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

GEORGE J. RATHBUN;

Witnesses EDWARD RATHBUN, H. J. TOMLINSON, Jr.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of latents,

Washington, D. C. 

